${"aaa.bbb.ccc" ^? "."}
${".aaa" ^? "."}
${"aaa." ^? "."}
${".aaa.bbb" ^? "."}
${"aaa.bbb." ^? "."}

${"aaa.bbb.ccc" $? "."}
${".aaa" $? "."}
${"aaa." $? "."}
${".aaa.bbb" $? "."}
${"aaa.bbb." $? "."}
